1. Field of the Invention
The present invention relates to a liquid crystal display device for use in a display apparatus of an electronic appliance for audi-visual purposes, a display apparatus of an OA (office automation) terminal, an advertisement display, and the like. In particular, the present invention relates to circuit boards (CBs) for supplying signals to a liquid crystal panel.
2. Description of the Related Art
Flexible CBs are used as circuit boards for supplying signals to a liquid crystal (LC) panel of an LC display device. For example, Japanese Laid-open Publication No. 4-115228 and Japanese Publication No. 8-28395 disclose LC display devices incorporating flexible CBs.
Neither of the above-mentioned publications discloses an LC display device in which terminal sections of a data-side glass substrate are provided in a narrow frame-like peripheral region.
A flexible circuit board according to the present invention includes: an insulative tape having a pair of long sides and a pair of short sides; a driving IC mounted on the insulative tape; an input terminal for receiving data signals and control signals to be sent to the driving IC; a first output terminal for outputting a signal from the driving IC; a second output terminal for outputting at least some of the data signals and control signals; and first and second power signal terminals for supplying a voltage to the driving IC, wherein the input terminal, the first output terminal, and the second output terminal are provided on one of the pair of long sides, the first power signal terminal being provided on one of the pair of short sides, and the second power signal terminal being provided on the other one of the pair of short sides.
In one embodiment of the invention, a notch is provided in the other one of the pair of long sides.
Alternatively, a flexible circuit board according to the present invention includes: an insulative tape having a pair of long sides and a pair of short sides; a driving IC mounted on the insulative tape; an input terminal for receiving a signal used on a data-side flexible circuit board; a first output terminal for outputting a signal from the driving IC; and a second output terminal for outputting the signal used on the data-side flexible circuit board, wherein the first output terminal and the second output terminal are provided on one of the pair of long sides, the input terminal being provided on at least one of the other one of the pair of long sides and inside the insulative tape.
In one embodiment of the invention, the signal used on the data-side flexible circuit board is at least one of a data signal, a control signal, and a power signal.
A liquid crystal display device according to the present invention includes: a scan-side glass substrate; a data-side glass substrate opposing the scan-side glass substrate; liquid crystal interposed between the scan-side glass substrate and the data-side glass substrate; an electrode transition portion provided between the scan-side glass substrate and the data-side glass substrate for transmitting a scanning signal output from the data-side glass substrate to the scan-side glass substrate; and data signal lines, control signal lines, and power signal lines provided on the data-side glass substrate.
Alternatively, a liquid crystal display device according to the present invention includes; a data-side flexible circuit board including: a first insulative tape having a pair of long sides and a pair of short sides; a first driving IC mounted on the first insulative tape; a first input terminal for receiving data signals and control signals to be sent to the first driving IC; a first output terminal for outputting a signal from the first driving IC; a second output terminal for outputting at least some of the data signals and control signals; and first and second power signal terminals for supplying a voltage to the first driving IC, wherein the first input terminal, the first output terminal, and the second output terminal are provided on one of the pair of long sides of the first insulative tape, the first power signal terminal being provided on one of the pair of short sides of the first insulative tape, and the second power signal terminal being provided on the other one of the pair of short sides of the first insulative tape; a scan-side flexible circuit board including: a second insulative tape having a pair of long sides and a pair of short sides; a second driving IC mounted on the second insulative tape; a second input terminal for receiving a signal used on the data-side flexible circuit board; a third output terminal for outputting a signal from the second driving IC; a fourth output terminal for outputting the signal used on the data-side flexible circuit board, wherein the third output terminal and the fourth output terminal are provided on one of the pair of long sides of the second insulative tape, the second input terminal being provided on at least one of the other one of the pair of long sides of the second insulative tape and inside the second insulative tape; a data-side glass substrate coupled to the data-side flexible circuit board and the scan-side flexible circuit board; a scan-side glass substrate opposing the data-side glass substrate; liquid crystal interposed between the scan-side glass substrate and the data-side glass substrate; an electrode transition portion provided between the scan-side glass substrate and the data-side glass substrate for transmitting a scanning signal output from the data-side glass substrate to the scan-side glass substrate; and data signal lines, control signal lines, and power signal lines provided on the data-side glass substrate.
Alternatively, a liquid crystal display device according to the present invention includes; a driving IC; a scan-side glass substrate having a first display driving terminal; a signal-side glass substrate having a second display driving terminal; and an electrode transition portion provided between the scan-side glass substrate and the signal-side glass substrate, wherein the driving IC is coupled to the second display driving terminal of the signal-side glass substrate; and the first display driving terminal of the scan-side glass substrate receives a signal, the signal being supplied to the driving IC via the electrode transition portion and the second display driving terminal.
In one embodiment of the invention, the signal is at least one of a data signal and a control signal.
In another embodiment of the invention, the liquid crystal display device further includes a scan-side printed crystal board for supplying the signal to the first display driving terminal of the scan-side glass substrate.
In still another embodiment of the invention, a seal region is provided in a periphery of the scan-side glass substrate and the signal-side glass substrate, the electrode transition portion being formed in the seal region.
Alternatively, a liquid crystal display device according to the present invention includes: a scan-side glass substrate having a first display driving terminal; a signal-side glass substrate having a second display driving terminal and a line; a first flexible circuit board having a first driving IC; and a second flexible circuit board having a second driving IC, wherein the first flexible circuit board is coupled to the scan-side glass substrate and the second flexible circuit board is coupled to the signal-side glass substrate, the first flexible circuit board being electronically coupled to the second flexible circuit board via an electrode transition portion provided between the scan-side glass substrate and the signal-side glass substrate.
Alternatively, a liquid crystal display device according to the present invention includes; a data-side printed circuit board having a power line; a signal-side glass substrate having a display driving terminal and a line; and a flexible circuit board having a driving IC, an output terminal being formed on one side of the flexible circuit board for outputting a signal to a liquid crystal display panel, and input/output terminals and a power terminal being provided on each of a pair of sides situated at an angle with the one side, wherein the output terminal of the flexible circuit board is electrically coupled to the display driving terminal of the signal-side glass substrate, the input/output terminal of the flexible circuit board being electrically coupled to the line of the signal-side glass substrate, the flexible circuit board having a portion overlapping the data-side printed circuit board, and the flexible circuit board being coupled to the data-side printed circuit board in the overlapping portion in such a manner that the power terminal is electrically coupled to the power line.
In one embodiment of the invention, the liquid crystal display device further includes a scan-side printed circuit board having a power line, the power line of the scan-side printed circuit board being coupled to the power line of the data-side printed circuit board via and FFC cable.
Alternatively, a liquid crystal display device according to the present invention includes: a data-side printed circuit board having a power line for supplying power; a signal-side glass substrate having a display driving terminal and a data-side signal/control signal line; and a flexible circuit board having a driving IC, an output terminal being formed on one side of the flexible circuit board for outputting a signal to a liquid crystal display panel, and input/output terminals and a power terminal being provided on each of a pair of sides situated at an angle with the one side, wherein the power terminal of the flexible circuit board is electrically coupled to the power line of the data-side printed circuit board, the flexible circuit board having a portion overlapping the signal-side glass substrate and, the flexible circuit board being coupled to the signal-side glass substrate in the overlapping portion in such a manner that the output terminal of the flexible circuit board is electrically coupled to the data-side signal/control signal line and the input/output terminal of the flexible circuit board is electrically coupled to the display driving terminal.
In one embodiment of the invention, the signal is a data signal.
In another embodiment of the invention, the signal is a control signal.
In still another embodiment of the invention, the first flexible circuit board is coupled in contact with the scan-side glass substrate on a first contact face, and the second flexible circuit board is coupled in contact with the signal-side glass substrate on a second contact face, the first contact face and the second contact face being interposed between the scan-side glass substrate and the signal-side glass substrate.
Alternatively, a liquid crystal display device according to the present invention includes; a liquid crystal display panel having a display section, the display section including a plurality of signal electrodes and a plurality of opposing scanning electrodes so that the plurality of signal electrodes and the plurality of opposing scanning electrodes together compose a matrix; at least one data-side flexible circuit board, each including; a driving IC for generating a scanning signal; and an output terminal for supplying the display signal to the plurality of signal electrodes; and a scan-side flexible circuit board for supplying a scanning signal for the plurality of scanning electrodes, wherein the driving IC is located between the display section and the output terminal of the data-side flexible circuit board.
In one embodiment of the invention, the output terminal is provided on one face of the at least one data-side flexible circuit board, and the at least one data-side flexible circuit board further includes, on the face on which the output terminal is provided, input/output terminals for inputting or outputting a signal to or from the driving IC.
In another embodiment of the invention, the at least one data-side flexible circuit board further includes input/output terminals for inputting or outputting a signal to or from the driving IC, and the output terminal of the at least one data-side flexible circuit board is located in a region surrounded by the input/output terminals and the driving IC.
In still another embodiment of the invention, the at least one data-side flexible circuit board includes notches at a side along which the output terminal is provided.
In still another embodiment of the invention, the driving IC on the at least one data-side flexible circuit board is coated with resin so that the resin does not substantially project from the surface of an insulation film provided on a back face of the data-side flexible circuit board.
In still another embodiment of the invention, an input terminal inputting signal to the liquid crystal display panel and a portion of a wiring lead coupled to the input terminal are provided on the liquid crystal display panel.
In still another embodiment of the invention, adjoining ones of the at least one data-side flexible circuit board are interconnected via a bridging circuit board.
Thus, in a flexible circuit board according to the present invention, input terminals for receiving data signals and control signals to be sent to a driving IC, a first output terminal for outputting a signal from the driving IC; and a second output terminal for outputting all or some of the data signals and control signals are provided in one line along one of the long sides of the flexible circuit board. As a result, all of these terminals can be simultaneously coupled to terminals on a data-side glass substrate. Since most of these terminals are provided on the long side of the flexible circuit board, the number of terminals provided on a short side of the flexible circuit board is reduced accordingly, thereby making it possible to reduce the dimension of the short sides of the flexible circuit board.
The construction according to the present invention also facilitates a pressure-attachment process. In particular, the adjustment in terms of press tool balance is facilitated. Herein, the term xe2x80x9cpress tool balancexe2x80x9d is defined as a balance between a tool for pressure-attaching substrates together and the substrates to be thus attached. A good xe2x80x9cpress tool balancexe2x80x9d generally illustrates a state where such a tool is in uniform contact with the substrates to be attached. For example, a poor xe2x80x9cpress tool balancexe2x80x9d in a press-attachment or soldering situation may emerge in the case where pressure-attachment occur in dispersed positions.
Furthermore according to the present invention, in the case where a plurality of said flexible circuit boards are employed so that the flexible circuit boards are disposed on a periphery of a data-side glass substrate, it is possible to utilize a terminal on the data-side glass substrate (which corresponds and is coupled to an input terminal and an output terminal of the flexible circuit board) as part of the wiring for transmitting signals to an adjoining flexible circuit board. As a result, a portion of a terminal on the data-side glass substrate may be utilized as part of the wiring for electrically coupling the input terminal and/or the output terminal of a flexible circuit board to those of an adjoining flexible circuit board, with the terminals of the adjoining flexible circuit boards being coupled by straight lines, for example. This helps eliminate redundant regions on the data-side glass substrate extending along the short side direction of the flexible circuit board.
Since the input/output terminals of data signals and control signals are provided along a long side of the flexible circuit board, it is possible to reduce the area for junction between an output terminal on a short side of a flexible circuit board of a liquid crystal display panel and an input terminal on a short side of an adjoining flexible circuit board. As a result, the frame-like peripheral region of the LC display device can be effectively narrowed.
In another embodiment of the present invention, the flexible circuit board may have notches along the other long side. This makes it possible to confirm the state of attachment between the flexible circuit board and the data-side glass substrate by eyesight.
A flexible circuit board according to a further embodiment of the present invention includes first output terminals for outputting signals from the driving IC, and second output terminals for outputting the signals used on the data-side flexible circuit board, the first and second output terminals being provided along one of a pair of long sides of the flexible circuit board. As a result, the frame-like peripheral region of a data-side glass substrate for coupling the flexible circuit board with the data-side glass substrate can be made narrow.
In a liquid crystal display device according to the present invention, an electrode transition portion for scanning signal lines is provided between a scan-side glass substrate and a data-side glass substrate, so that a scanning signal input from the data-side glass substrate can be supplied to the scanning signal lines on the scan-side glass substrate via the electrode transition portion. This eliminates the need for coupling the scan-side glass substrate with the data-side glass substrate by the use of jumper leads or the like. As a result, the wiring design for the data signal lines, control signal lines, the power signal lines, and the like is simplified, thereby facilitating the overall design process for the liquid crystal display device of the present invention.
In the case where the data-side flexible circuit boards and the scan-side flexible circuit boards are oriented in the same direction, it is possible to simultaneously press-attach such flexible circuit boards, and to simultaneously apply a moisture-resistant material on the wiring.
In the case where the data-side flexible circuit board is disposed so as to fit within the data-side glass substrate, it becomes possible to reduce circuit boards and hence the manufacturing cost, improve the reliability (in terms of likelihood of disruption of lines connected to input and/or output terminals), and improve vibration resistance.
In the case where the data-side flexible circuit boards or the scan-side flexible output boards are press-attached onto the data-side glass substrate by means of an anisotropic conductive film, it is possible to conveniently peel the data-side or scan side flexible circuit board. This will facilitate the repair of the liquid crystal display device.
Thus, the invention described herein makes possible the advantage of providing an be LC display device in which terminal sections of a data-side glass substrate are provided in a narrow frame-like peripheral region.